Boat hull construction



A. w. w. VAN HOORN BOAT HULL CONSTRUCTION Aug. 3, 1943.

lNVEN-TOR 41/9597 I A/VA o ,w Z; I: mar/;

A ORNEY 4 Sheets-Sheet 1 Filed Nov. 2, 1938 Aug. 3, 1943;

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A. W. W. VAN HOORN BOAT HULL' CONSTRUCTION Filed Nov. 2, 1938 4 Sheets-Sheet 2 llllll s a Z 5 INVENTOR 415527 111/14 1494 4 00? ATTO R N EY Aug. 3, 1943. A w. w. VAN HOORN BOAT HULL CONSTRUCTION Filed Nov. 2, 19 8 4 Sheets-Sheet 3 INVENTOR A155??- IL IIK m A aom/ ATTORNEY 1943- A. w. w. VAN HOORN 2,326,080

BOAT HULL CONSTRUCTION Filed Nov. 2, 1938 4 Sheets-Sheet 4 INVENTOR. Azemr WWW/Mam ATTORN EY Patented Aug. s, 1943 UNITED STATES PATENT OFFICE BOAT HULL CONSTRUCTION Albert W. W. van Hoorn, Holly ()ak, Del. Application November 2, 193$, Serial No. 238,326

Claims. (01. 9-4;)

This invention relates to anew and improved construction for boats and to a process of making the same.

It is an object of this invention to devise a new and improved hull which can be constructed with greater ease and at less expense, with greater assurance of the proper form of the hull when completed and more particularly to devise a hull which is separated into a plurality of longitudi nal sections or pods along; planes parallel to the center line, whereby the separate pods may be easily constructed and easily assembied.

It is a further object to so simplify the construction and the method of making a hull that boats of medium size may be constructedby what may be relatively spoken of as quantity production without the individual attention required by previous 'methods.

. It is a further object to provide a hull which, in case of accident to one or more pods can be completely repaired by replacing the damaged pod with an interchangeable unit of the same construction with a minimum of expense and time. a

It is a further object to provide a hull which,

.if desired, may be sold and shipped in sections and readily assembled at the water front or at any convenient location either by an assembling crew or by an amateur without any difficulty in maintaining the symmetry of the lines.

It is a further object in the making of wooden boats to provide a method by which the parts of the skeleton maybe made of sawn timbers in stead of bent wood and which,'nevertheless, will have all of the principal strains in'ythe wood transverse to the grain.

It is a further object to provide a system of boat buildingby which a plurality of interchangeable sections may be provided for each of'the several sections needed to build the boat, which sections may be assembledto provide a complete hull and in this manner a greater standardization of construction may be secured with a corresponding reduction in individual labor.

The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described and the scope of the application of which will be indicated in the claims. a

For a fuller understanding of the nature and objects of-the invention, reference should be had to the following detailed description, taken in connection with the accompanying drawings, in which: a

Figure l is a side elevation of a hull constructed in accordance with this invention.

Figure 2 is a perspective viewof a section of the hull as itis being built on the construction table.

Figure 3 is a center line cross section of the complete hull of Figures 1 to 3. V

Figure 4 is a detail showingthe dovetail con- 'nection betweenthe rib sections and the longi tudinal stringers.

Figures 5, 5 and '7 are views similar to Figures 2, 3 and i but showing the invention as applied to the construction of a hullswith a metal frame.

Figure 8 is a detail of a clamping means suitable for use in holding the longitudinal string ers on the table.

Figure 9 isa side elevation of a hull of larger size embodying the invention.

. Figure 10 is a central longitudinal section of the hull of Figure 9.

Figures 11 and 12 are detail sections of alternative constructions along the line ll-ll of Figure 9.

In the construction of boats it has been proposed to set upon the construction floor the keel and then attach a plurality of cross members or ribs. to the. keel holding the free ends in place by braces attachedto them while the planking is nailed in place. ,In accordance with such a system, the attachment of the planks, which have to be bent to shape, exerts sufiicient force against the ribs to bend the ribs out of shape unless special care is taken to the contrary, and so requires avery careful bracing of the ribs. The attachment of the planks is usually commenced at the keel and in order to prevent the warping of the hull; the two sides are built up simultaneously by attaching to the ribs one or more planks on one side of the keel and then a substantially equal number on the other side. This presents dificulty for as the keel rests on the floor, the installing or fastening of the first few planks is a difficult task the ribs themselves being all bent, materially tend to change their shape and hence to deform the hull. Such construction is expensive and two hulls made from the same blue prints may in fact differ in shape. Attempts to use sawn ribs in place of bent ribs are not satisfactory under such a system since the diiierent parts of the rib lie at such diifererit angles to each other that atleast at some point the strains will be across thegrain of the wood.

Sometimes this system is modified by inverting the hull and building it with the keel up. This offers many of the same difficulties as in the preceding system, the hull itself being in the way of the workman, making it difficult to fasten the planks on the skeleton.

. In accordance with this invention 1. 1 'r. on 1.11.11]! 1-.)

. divided by a series of planes intersecting in a line along the center of the boat, thus forming longitudinal sections. Which I prefer to call pods. Each of these pods is defined by a longitudinal member on each edge, herein referred to as a stringer, and between these stringers transverse to them, extend sections of ribs which are firmly I fastened to them.

In constructing larger hulls each of these pods may in turn be divided transversely to make sections easy to handle and construct and in any case the reinforcing members which run along the edges of the pods or sections furnish a practical point of attachment for transverse reinforcing or.

deck supporting beams. If desired a plate may be clamped between the pods to give greater stiffness or afford better means of support.

Referring now to the drawings and in particular to Figures 1 and 3, the hull, as shown, is formed of four pods Id, ll, 52 and i3 which meet along planes AB, AC and AD. These planes intersect at their plane of intersection are provided with bilge stringers l8 and ii respectively, which, be cause each lies in the plane of intersection and each conforms to the hull form, may be cause to lie flat against each other as shown.

- I'he pods l3 and i2 correspond respectively to the pods Id and II, but of course are reverse to them. The pod l3 having a deck shelf or stringer l8 and the pods i2 and i3meeting along-a bilge stringer 2B and El. The pods H and i2 have along the meeting edges check piecesor keel stringers 22 and 23, which are provided with the dovetails into which the rib sections are fitted. These keel stringers are fastened to keel'sections 22a and 23a each of which forms one half of the permanent keel. The pods H and I2 being fastened withfbolts which in the center of the boat,

fore and aft, may pass through the check pieces and through the keel sections but at the ended the host may pass through the keel and stern "sections only, This division of the keel facilitates "cutting the keel to provide a shaft alley for the "ingmaterial adapted to insure a tight joint at 'the connection.

One of the particular advantages of this type of construction'is the ease with which the separate pods may be built and this will now be devscribed by reference to Figures 2 and l. I have 'chosen to illustrate this construction in connection with the construction of pod ill but the other pods have the same construction, except for the shape and they are constructed in the same mam ner.

he nunirart'a designates a table or bench of a suitable height-to make all parts of the construction accessible. Upon the surface of this table is marked the contour of, for example, the bilge stringer iii and the stringer is fastened flat upon itlwith the edge of the stringer that to illustrated, there is provided upon the tabla series of holes corresponding to the holes he stringers, which are to receive the fastening bolts 28 in the stringer l6 and the string-er itself is fastened to the table by bolts passing through these holes, being thus not only firmly held to the table but also firmly held against being bent out of shape the attachment to the planks as the latter are applied.

In Figure 8 is shown an alternative construction in which the holes in the table are on one side of the stringer and the stringer is held to the table by J shaped claimps 28a having a stem 23b fitting within the holes, and having the short leg of the -..i 230 bearing against the stringer. Such a clamp will hold tightly when driven into its hole, but will readily release if knocked side ways by a hammer.

The stringer 55 itself is provided upon its u per side as it lies upon the table, with a series of dovetail slots 3! corresponding to the loos.- tion of the rib sections to be attached. Those slots are all parallel and each of, them is perpendicular to the-center line of the boat and parallel to the plane In the construction here shown the'deck shelf or stringer M- is not continuous but is composed of two sub-stringers i554 and H ll) at different levels from each-other; The former extending along the fore part of the boat and the latter along the stern portion; the difference in level being in accordance with the design of the hull to be formed. Each ofthese sub-stringers la and I l?) is provided with a series of dovetail slots 32 cut on its underside opposite the slots in the bilge stringers i6 and thus corresponding to. the position of the upper edge of the rib section-of the skeleton; These slot-s as in the case of the slots in the bilge stringers, are all parallel to each other and parallel to the horizontal in the form in which the section finally liesin the hull.

At the point where the two sub-stringers overlie, as shown at Eric, a special construction may be provided, if desired, thus short spacing sections l id may be usedto keep the over-lying sectionsproperlyspaced from each other.

Afterthe bilge stringer is fastened to the ta ble, as above described, the upper or sub-stringer Ma isheld in place by attaching its front portion to the stem section 3 1 and by inserting one of the ribs 315 nearits stern end into a dovetail st in the bilge stringer and into adovetail 32 in the 'deck shelf simultaneously. The sub-stringer I 'lb may be similarly held in place by ribs 36 and (ii respectively. Whereupon the remaining ribs 38 may each, one by one, be forced into the slots at top and bottom by suitable pressure, they being particularly designed to fit very tight.

They are preferably forced into place by pressure, as for example by clamps, and when in placethy form a very rigid skeleton frame which is rigidly supported from the table.

If the an-gularity between the terminal planes of the pod is not great, it is possible to make the dovetails 3i and 32 parallel to eachother, which greatly facilitatesinserting the stringer in the dovetail.

The construction offers so great rigidity that the planks may be nailed directly to the'skeleton thus formed without special precautions, at least in medium sized boats; the ribs themselves being rigid enough to take the strain.

.As soon as the planks on the' top and bottom edge of the pod have been nailed in place, being attached as they are both to the stringer and to i the ribs, they serve as a means of holding the rib dovetailed tongue from sliding in the dovetail slot, thus further rigidifying the whole.

By this construction the pod is substantially upright while it is being constructed, which pleted it may be removed iromthe 'tableby removing'thebolts 1-28 and thereafter the remaining pods may be built. It may be observed that in its contour and bolt positions the lower bilge stringer of the pod it is identical with the upper bilge stringer of the pod l2 and the upper bilgestringer of the pod l i is identical with the lower bilge stringer of the pod i3, so that for the complete construction-of the four pod hull it would be necessary to have two setsof markings only on the table.

When all of the sections have been built as described, the four pods are bolted together to a form a compete hull. Preferably, the keel stringers 22 and 23 are so designed as to engage the side faces of the keel it so that a single set of bolts may bolt the lower pods and the keel together.

In the form or the invention disclosed in Fi ures 5, 6 and 7, the general division of the hull and the assembly is-identical withthat which has been described, except that the stringers in the rib sections are of metal and the ribs are welded to the stringers as shown in Figure 7 in place of being dovetailed into them as in the case where wood is used. The skin itself may be made of any suitable material but in any event it'will be seen that the same easy assembly will be found in the construction as in the first embodiment of the invention because of the ready accessibility of the parts.

In the form of the invention disclosed in Figures 9 to 12 the invention is shown asapplied to the construction of a larger hull, as for example a metal tanker and as there shown the hull may be divided by transverse planes FF and GG as well as by the planes parallel to the center line as in the previous modification. Thus each of the pods H, I, J, K, L or M is divided into a series of sections I-ll, H2, etc., at these transverse planes.

These pod sections Hi, H2, etc, may be bolted together by bolts extending through the terminal ribs thereof as shown in Figure ,11 or, if desired, transverse plates N may be inserted between the flanges of adjacent ribs to be bolted to both ribs thus furnishing a rigid reinforcing member to strengthen the hull at that point.

In the construction of many steel hulls the body of the boat has parallel sides so that during all of the intermediate hull sections the ribs will be vertical and the plates attached directly thereto without the necessity of bending.

The cross beams and the deck supporting beams may be attached, if desired, to the longitudinal stringers or to the adjacent rib sections where the' pod sections are connected together.

This method'ofassembly greatly facilitates the building of large hulls; r I

j By the above construction it willbe seen that the hull can be readily constructed: and assembled. Moreover, because of the form of the construction, allof the elements may be formed of sawn members making it unnecessary to bend the woodto shape and relieving the hull of the strains imposed by the gradual distortion of the bent members when released from the strain.

Since certain changes may be made/in the above construction and different embodiments of the invention couldbe made without departing from the scope thereoflit isintended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. y it is also to be understood that thefollowing claims are intended to cover all of the generic and specific features of the invention herein de scribed, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

, throughout, said skeleton comprising a plurality of curved stringers extending in a direction from stem -.to stern and curved to conform to the shape of said hull, said stringers being arranged in pairs, a plurality of curved rib sections extending from each'of said stringers to the other stringer of said pair and having both ends of each of said rib sections firmly attached to said stringers'to form apod frame conforming to a .portion of the curved contour of the hull, said skeleton being of such strength as to resist the strains incidentto the bending of the skin surface from the flat to the progressively curved contour of the hull, the adjacent stringers of adjacent pod frames having longitudinal surfaces lying in a plane substantially parallel to the center line of the hull and being attached together along said plane throughout their lengths to join said frames to form a hull skeleton.

2. A device in accordance with claim I having a skin surface over said hull skeleton'firmly attached to said stringers and to said ribs at the joint between them, whereby the said joint is firmly reinforced by said skin.

3. A device in accordance with claim 1 in which there are provided two such pod sections on each side of the longitudinal vertical center line of the boat, the adjacent stringers of each of said two pod sections contacting along a plane inclined to the vertical and being firmly bolted together.

' place along said jointsv without displacing said stringers.

5. A pod for a hull, said hull being of the type having progressively curved sections, said pod comprising a pair of stringers, each curved throughout its length to correspond to the section of the progressively curved hull along a plane substantially para cen er ie b said stringers to the other andgh firmly attached to its. .contesncndms I said ribs ccmprisingqthe meansei m W1 -stringers are connected together to orm. 5 ipQ .h! sai frame, said rib. sections bei-ng .ofisuchstrgength and so, firmly attached tosaid: stringers-fies. o

. holdthe said pod frame-to the. hull. contour, independent of Qther-suppOBtanda skin is riace bent about the skeleton formed by said ribs-Band V stringers, from the. flatgandretainediinsaid iproe ..-gressi vely. curved contour by isuch skeleton,

g 6. A pod for av hull, said hull beingcftheltype having progressivelycurved. sections, said .:pod

oomprising a pair of stringers each curved throughout its length 110 v co'rrespond. to they skin of the hull along a plane substantially. parallel itorthe center line of -the.:'hull,rone of-xsaidstringers having a plane-terminal surfacesubstantially :eo'riforming to one. of said =planes,;said stringers being-spaced apartand substantially parallel .to

each other, a plurality of curvedribsections-each conforming to the contour of the hull *andeX- tending from one of said stringers to the/other, said ribs comprising the @means by which the stringers are connectedztogether, .askinzsurface fastened upon'the exteriorof'theskeleton formed by said ribs andstringers, said rib sectionsbeing of such strength and so.firmlyattached toxsaid stringersto hold the said pod skeleton to. the

111111 contour without o.ther='support even against the strains imposed by the bending of saidskin from the fiat to the 1 curvedcontour :of the hull. JA device'in accordance with claim '6 in .ibiatssbr said ski .20-

h ch: the m a s o achin ea S in e each rib comprises a dove-taile d.[jqint. eachgjoint aton st n e bei ub tan ia l Para le he c esn nd n J int oi h othe t n whereby .eachrib .sectionmay bejforced into place along said joints without displacing said t ies 8. A device. accordance with claim 6 in whichthbims ns of t ac i eac st in e to each r premises a clove-tailed joint, each joint tt e sr be wh tant al a a le to qqrras m i 0 a? o h O h tr n whereby each rib section mayflbe. forced into place algae sa d m nt Without lac as Said st 'ngers, a a skin surface. laid overtheends a said ove ailed ints" a d-fi ml w n r lasanqt aid string-ar a din w ne v s s ate- 3 1M? a d q eils a A. ske e on a 5., 1 1. 11- 9 e we he ie pro re sive cur ed; ct o s: hr u hout filrma a ut a keleto lsai eton wmm s llea 3 mlitv 0: sect qn on. ac side o he 462 9 enter ip aneci the. hu l x e d n n. he di e;- tion from stem, to stern, each comprising a self- ,suppolzting frame, each of said sections having a longitudinal, stringer curved to correspond to i-theecurvature of theJhull, on eachredge thereof,

and [a plurality of rib sections also curved to correspond to the curvature of the hull; extendtingrbetween. and firmlyattached to said 7 tringers toiocm. with-said stringers a self-supportinghull section, the. adjacent stringer of the hull sections on .each'side of the. said center planelying in .a common plane parallel to the center line of the hull-and being firmly attached together to. Orm said hull.

10 A device in accordance with claim :1, havi-ng -a skin suriace-over said-skeleton and. firmly attached thereto comprising a plurality. .ofindividual horizontal strips bent to conform to the progressively-curved section of the skeleton.

' ALBERT W. W. VAN HOORN. 

